Shrink packing system

ABSTRACT

A packing unit of a shrink packing system which shortens time required for a packing process. For this purpose, the packing unit includes four supporters arranged at both sides of a transfer conveyer, two elevators combined with the four supporters so as to be upwardly and downwardly movable, and four telescopic arms combined with the two elevators so as to be movable in the moving direction of the transfer conveyer and to be extensible and retractable in the lengthwise direction.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority benefit of Korean PatentApplication No. 10-2012-0010373, filed on Feb. 1, 2012 in the KoreanIntellectual Property Office, the disclosure of which is incorporatedherein by reference.

BACKGROUND

1. Field

Example embodiments of the following disclosure relate to a shrinkpacking system in which electric home appliances, such as refrigeratorsand washing machines, are packaged with a shrink film.

2. Description of the Related Art

In general, shrink packing is a method of packing a product by coveringthe product with a shrink film, and then shrinking the shrink film bysupplying hot air to the product. Recently, such shrink packing methodshave used a low-density polyethylene (LDPE) film, which has few harmfulsubstances and is recyclable. Thus, the LDPE film has been highlightedas an environmentally friendly packing method, which substitutesconventional methods of packing a product with a paper box.

Such shrink packing methods may be divided into a method of coveringproducts with a shrink film in the sideward direction and a method ofcovering products with a shrink film in the downward direction accordingto packing directions.

Generally, a packing unit using the downward covering method includesone supporter provided at one side of the moving direction of a transferconveyer transferring products, one elevator combined with the supporterso as to move upwards and downwards, two cantilevers combined with theelevator so as to move forwards and backwards in the moving direction ofthe transfer conveyer, four arms combined with the two cantilevers so asto move forwards and backwards in the direction perpendicular to themoving direction of the transfer conveyer, and four clamping fingersprovided at the ends of the four arms so as to grip the shrink film.

Therefore, only when the elevator moves downwards so that a product iscovered with the shrink film and then moves upwards again, the productcovered with the shrink film may be transferred to a hot air shrinkingunit through the transfer conveyer. Further, since only one end of eachof the cantilevers is fixed to the elevator, when the elevator movesupwards and downwards at a high speed, the cantilevers may vibrate andmay cause a limit in upward and downward movement of the elevator, whenoperating at the high speed, thereby reducing the effectiveness ofshrink film methods.

SUMMARY

Therefore, it is an aspect of the present disclosure to provide a shrinkpacking system which shortens time required for a process of covering aproduct with a shrink film and transferring the product covered with theshrink film to a hot air shrinking unit through a transfer conveyer in amethod of covering products with the shrink film in the downwarddirection.

Additional aspects of the disclosure will be set forth in part in thedescription which follows and, in part, will be obvious from thedescription, or may be learned by practice of the disclosure.

In accordance with one aspect of the present disclosure, a shrinkpacking system includes a transfer conveyer transferring products, afeeding unit continuously feeding a shrink film in the shape of anenvelope wound on a roll, an opening unit receiving the shrink film fedfrom the feeding unit and spreading the shrink film, a packing unitcovering a product with the shrink film by moving in the downwarddirection of the product while gripping the spread shrink film, and ashrinking unit shrinking the shrink film covering the product using hotair, wherein the packing unit includes four supporters arranged at bothsides of the transfer conveyer, two elevators supported by the foursupporters and provided so as to be upwardly and downwardly movable,four telescopic arms combined with the two elevators so as to beslidable in the leftward and rightward directions, and provided so as tobe extensible and retractable in the forward and backward directions,and four clamping fingers provided at the front ends of the fourtelescopic arms.

The two elevators may move upwards or downwards together.

The four telescopic arms may be extended or retracted together.

When the opening unit spreads the shrink film, the telescopic arms maybe extended in the forward direction so that the clamping fingers maygrip the shrink film.

After the elevators have moved downwards under the condition that theclamping fingers grip the shrink film and then covered the product withthe shrink film, the telescopic arms may be retracted in the backwarddirection.

When the elevators move upwards under the condition that the telescopicarms are retracted in the backward direction, the transfer conveyer maymove to transfer the product covered with the shrink film to theshrinking unit and to transfer the next product not covered with theshrink film to the packing unit.

Each of the elevators may include sliding rails provided in the leftwardand rightward directions, and each of the telescopic arms may include asliding block combined with the sliding rails so as to slide.

Each of the elevators may further include a pinion gear and a drivemotor driving the pinion gear, and each of the telescopic arms mayfurther include a rack gear engaged with the pinion gear so as toreceive driving force.

Each of the telescopic arms may include a first arm member combined withthe elevator, a slide member combined with the first arm member so as tobe movable in the forward and backward directions with respect to thefirst arm member, and a second arm member combined with the slide memberso as to be movable in the forward and backward directions with respectto the slide member.

In accordance with another aspect of the present disclosure, a shrinkpacking system includes a transfer conveyer transferring products, afeeding unit continuously feeding a shrink film in the shape of anenvelope wound on a roll, an opening unit receiving the shrink film fedfrom the feeding unit and spreading the shrink film, a packing unitincluding two elevators provided so as to be upwardly and downwardlymovable, and four telescopic arms combined with the two elevators so asto be slidable in the leftward and rightward directions and provided soas to be extensible and retractable in the forward and backwarddirections, and a shrinking unit shrinking the shrink film covering theproduct using hot air.

When the opening unit spreads the shrink film, the packing unit may movedownwards while gripping the shrink film under the condition that aproduct is stationary, and thus cover the product with the shrink film.

When the product is covered with the shrink film, the packing unit movesupwards and simultaneously, the product covered with the shrink film maybe transferred to the shrinking unit and another product not coveredwith the shrink film may be transferred to the packing unit.

In accordance with a further aspect of the present disclosure, a packingunit includes four supporters arranged at both sides of a transferconveyer transferring products, two elevators supported by the foursupporters and provided so as to be upwardly and downwardly movable,four telescopic arms combined with the two elevators so as to beslidable in the leftward and rightward directions, and provided so as tobe extensible and retractable in the forward and backward directions,and four clamping fingers provided at the front ends of the fourtelescopic arms.

In accordance with a further aspect of the present disclosure, a shrinkpacking system to shorten a time of a packing process is provided,including: a packing unit to cover a product with shrink film by movingin a direction of the product while gripping the shrink film; and ashrinking unit to shrink the shrink film covering the product using hotair, wherein when the product is covered with the shrink film, thepacking unit moves upwards and simultaneously, the product covered withthe shrink film is transferred to the shrinking unit and another productnot covered with the shrink film is transferred to the packing unit.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects of the disclosure will become apparent andmore readily appreciated from the following description of theembodiments, taken in conjunction with the accompanying drawings ofwhich:

FIG. 1 is a schematic view of a shrink packing system, according to anexample embodiment of the present disclosure;

FIG. 2 is a front view illustrating a feeding unit, an opening unit anda packing unit of FIG. 1;

FIG. 3 is a perspective view of the packing unit of FIG. 1;

FIG. 4 is an exploded perspective view illustrating a connectionstructure between an elevator and telescopic arms of the packing unit ofFIG. 1;

FIG. 5 is an assembled perspective view illustrating the elevator andthe telescopic arms of the packing unit of FIG. 1;

FIG. 6 is an exploded perspective view illustrating the structure of thetelescopic arm of the packing unit of FIG. 1;

FIG. 7 is an assembled perspective view illustrating the structure ofthe telescopic arm of the packing unit of FIG. 1; and

FIGS. 8 to 12 are exemplary views illustrating a process of covering aproduct with a shrink film through the packing unit of FIG. 1, accordingto example embodiments of the present disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to the exemplary embodiments of thepresent disclosure, examples of which are illustrated in theaccompanying drawings, wherein like reference numerals refer to likeelements throughout.

FIG. 1 is a schematic view of a shrink packing system, according to anexample embodiment of the present disclosure, FIG. 2 is a front viewillustrating a feeding unit, an opening unit and a packing unit of FIG.1, and FIG. 3 is a perspective view of the packing unit of FIG. 1.

With reference to FIGS. 1 to 3, a shrink packing system 1, according toan example embodiment of the present disclosure may include a transferconveyer 20 transferring a product 10, an alignment unit 21 aligning theproduct 10, a feeding unit 30 feeding a shrink film 60, an opening unit40 spreading the shrink film 60 fed by the feeding unit 30, a packingunit 100 moving downwards while gripping the shrink film 60 spreadthrough the opening unit 40 so as to cover the product 10 with theshrink film 60, and a shrinking unit 50 shrinking the shrink film 60 ofthe product 10 covered with the shrink film 60 through the packing unit100 using hot air.

Depending on embodiments, the transfer conveyer 20 may transfer theproduct 10 so that the product 10 may sequentially pass through thealignment unit 21, the packing unit 100, and the shrinking unit 50.

The product 10 may be an electric home appliance, such as a refrigeratoror a washing machine, for example. Further, design specifications of therespective constituent equipments of the shrink packing system 1 inaccordance with an example embodiment of the present disclosure, suchas, the packing unit 100, the shrinking unit 50, etc., may be properlymodified according to the size of the product 10, and may thus beapplied regardless of the size of the product 10.

The product 10 may enter the shrink packing system 1 in accordance withan example embodiment of the present disclosure under the condition thatthe upper, lower and side edges of the product 10 are respectivelycovered with a cushioning material (not shown).

When the product 10 enters the alignment unit 21, the alignment unit 21may align the product 10 at the central region, however, the presentdisclosure is not limited thereto. That is, the alignment unit 21 mayalign the product 10 at regions of the transfer conveyer 20, other thanthe central region. The product 10 having passed through the alignmentunit 21 may reach the packing unit 100, and stop in the packing unit 100for a short time while the packing unit 100 covers the product 10 withthe shrink film 60.

The feeding unit 30 may be arranged at one side of the packing unit 100,and the shrink film 60 may be wound on a roll and then fed to theopening unit 40 through the feeding unit 30. The feeding unit 30 mayinclude a film feed roller (not shown) moving the shrink film 60 and afilm feed motor (not shown) driving the film feed roller (not shown),and the shrink film 60 moving through the film feed roller (not shown)may be fed to the opening unit 40 through at least one buffer 33.

The shrink film 60 in accordance with an example embodiment of thepresent disclosure may have the shape of an envelope, such that an endportion is open, and the other portion of which may be closed to cover aproduct in a wrapping way (referring to FIGS. 10 & 11, for example) andmay be cut after the shrink film 60 covers a product by a cutter (notshown) or by a partial pre-cutting method. Further, the shrink film maybe wound on the roll in a state in which the shrink film 60 is foldedflat. Depending on embodiments, the shrink film 60 may be in othershapes or be wound in other ways, and thus, the present disclosure isnot limited to the above. The schematic cross-sectional shape of theshrink film 60 is illustrated in a portion shown by an alternate longand two short dashes line in FIG. 2. Further, the shrink film 60 may bea low-density polyethylene (LDPE) film, which has few harmful substancesand is recyclable.

The opening unit 40 may include a horizontal frame 41, and a pluralityof opening blades 42 and 43 hinged on to the horizontal frame 41 so asto be rotatable and to cause the shrink film 60 to be adhered theretousing hot air. After the shrink film 60 is adhered to the plurality ofopening blades 42 and 43, the plurality of opening blades 42 and 43 maybe rotated to opposite sides to open the shrink film 60. Such an openingunit 40 may be disposed above the packing unit 100, and be supported bysupporters 200 a, 200 b, 200 c and 200 d (with reference to FIG. 3).

The packing unit 100 may move downwards while gripping the shrink film60 opened by the opening unit 40, thereby covering the product 10 withthe shrink film 60. The packing unit 100 in accordance with an exampleembodiment of the present disclosure may include four supporters 200 a,200 b, 200 c and 200 d arranged at both sides of the transfer conveyer20, two elevators 300 a and 300 b supported by the supporters 200 a, 200b, 200 c and 200 d and provided so as to be upwardly and downwardlymovable, and four telescopic arms 400 a, 400 b, 400 c and 400 d combinedwith the two elevators 300 a and 300 b and protruding toward thetransfer conveyer 20.

The supporters 200 a, 200 b, 200 c and 200 d may be formed in the shapeof a column supported by the ground surface, however, the presentdisclosure is not limited thereto. That is, the supporters 200 a, 200 b,200 c, and 200 d may be formed in shapes other than the shape of acolumn. Further, the elevators 300 a and 300 b may be provided so as tobe upwardly and downwardly movable along the supporters 200 a, 200 b,200 c and 200 d. The upward and downward movement of the elevators 300 aand 300 b may be implemented through various configurations, and, forexample, may be implemented through weights and chains which are notshown in the drawings.

For example, the two elevators 300 a and 300 b may move downwardstogether when the product 10 is covered with the shrink film 60, and maymove upwards together after the product 10 has been covered with theshrink film 60. However, the above is exemplary, and thus, the presentdisclosure is not limited thereto.

Two of the four telescopic arms 400 a, 400 b, 400 c and 400 d may becombined with each of the two elevators 300 a and 300 b, and thetelescopic arms 400 a, 400 b, 400 c and 400 d may be combined with thetwo elevators 300 a and 300 b so as to be forwardly and backwardlymovable in the moving direction of the transfer conveyer 20. That is,the respective telescopic arms 400 a, 400 b, 400 c and 400 d may becombined with the elevators 300 a and 300 b so as to be slidable in theleftward and rightward directions.

The telescopic arms 400 a, 400 b, 400 c and 400 d may be provided so asto be extended or retracted in the lengthwise direction, i.e., forwardsor backwards, and clamping fingers 500 a, 500 b, 500 c and 500 d (asshown in FIG. 4) which may grip the shrink film 60 may be provided atthe front ends of the telescopic arms 400 a, 400 b, 400 c and 400 d.

The four telescopic arms 400 a, 400 b, 400 c and 400 d may be extendedtogether when the telescopic arms 400 a, 400 b, 400 c and 400 d grip theshrink film 60 and then cover the product 10 with the shrink film 60,and be retracted together after the telescopic arms 400 a, 400 b, 400 cand 400 d have covered the product 10 with the shrink film 60. However,the above is exemplary, and thus, the present disclosure is not limitedthereto.

In the packing unit 100 having the above configuration in accordancewith an example embodiment of the present disclosure (referring, forexample, to FIG. 4), the elevators 300 a and 300 b move upwards anddownwards, and the telescopic arms 400 a, 400 b, 400 c and 400 d slidein the leftward and rightward directions and are extended and retractedin the forward and backward directions. Therefore, the clamping fingers500 a, 500 b, 500 c and 500 d provided at the front ends of thetelescopic arms 400 a, 400 b, 400 c and 400 d may have 3 degrees offreedom.

Further, when the telescopic arms 400 a, 400 b, 400 c and 400 d areretracted, the length of the telescopic arms 400 a, 400 b, 400 c and 400d is shortened, and thus, vibration of the telescopic arms 400 a, 400 b,400 c and 400 d when the telescopic arms 400 a, 400 b, 400 c and 400 dmove upwards and downwards may be reduced.

Hereinafter, the connection structures between the elevators 300 a and300 b and the telescopic arms 400 a, 400 b, 400 c and 400 d and theextension and retraction structures of the telescopic arms 400 a, 400 b,400 c and 400 d will be described in detail with reference to theaccompanying drawings.

FIG. 4 is an exploded perspective view illustrating the connectionstructure between the elevator and the telescopic arms of the packingunit of FIG. 1, FIG. 5 is an assembled perspective view illustrating theelevator and the telescopic arms of the packing unit of FIG. 1, FIG. 6is an exploded perspective view illustrating the structure of thetelescopic arm of the packing unit of FIG. 1, and FIG. 7 is an assembledperspective view illustrating the structure of the telescopic arm of thepacking unit of FIG. 1.

Since the connection structures between the two elevators 300 a and 300b and the four telescopic arms 400 a, 400 b, 400 c and 400 d of thepacking unit 100 in accordance with an example embodiment of the presentdisclosure are the same, only the connection structure between theelevator 300 b and the telescopic arms 400 c and 400 d will be describedand a description of the other connection structure, i.e., between 300 aand the telescopic arms 400 a and 400 b, will be omitted.

As shown in FIGS. 4 and 5, sliding rails 310 and 311 may be provided onthe elevator 300 b in the lengthwise direction of the transfer conveyer20 so as to support the telescopic arms 400 c and 400 d and to guidesliding of the telescopic arms 400 c and 400 d, and the telescopic arms400 c and 400 d may include sliding blocks 410 and 411 combined with thesliding rails 310 and 311.

Rack gears 420 and 421 provided in the lengthwise direction of thesliding rails 310 and 311 may be fixed to the sliding blocks 410 and411. A pinion gear 320 engaged with the rack gears 420 and 421 totransmit driving force, a drive motor 330 driving the pinion gear 320,and rack gear clampers 340 and 341 supporting the rack gears 420 and 421may be provided on the elevator 300 b.

The two rack gears 420 and 421 may be engaged with the upper and lowerparts of the one pinion gear 320 so as to receive driving force from theone pinion gear 320. Therefore, when the pinion gear 320 is rotated inone direction, the telescopic arms 400 c and 400 d may move close toeach other, and when the pinion gear 320 is rotated in the otherdirection, the telescopic arms 400 c and 400 d may move away from eachother.

Through the above-described configuration, the telescopic arms 400 c and400 d may be supported by the elevator 300 b and slide in the leftwardand rightward directions.

Next, the extension and retraction structures of the telescopic arms 400a, 400 b, 400 c and 400 d will be described with reference to FIGS. 6and 7. Since the extension and retraction structures of the fourtelescopic arms 400 a, 400 b, 400 c and 400 d are the same, only theextension and retraction structure of the telescopic arm 400 c will bedescribed and a description of other retraction and retractionstructures, i.e., for 400 a, 400 b, and 400 d, will be omitted.

The telescopic arm 400 c may include a first arm member 430 fixed to thesliding block 410 (with reference to FIG. 4), a slide member 440combined with the first arm member 430 so as to be movable in thelengthwise direction, and a second arm member 450 combined with theslide member 440 so as to be movable in the lengthwise direction.

Support rails 443 and 444 may be provided on both side surfaces of theslide member 440 in the lengthwise direction, and holding blocks 434 and454 slidably combined with the support rails 443 and 444 may be providedon the first arm member 430 and the second arm member 450. Therefore,the second arm member 450 may be slidably supported by the slide member440, and the slide member 440 may be slidably supported by the first armmember 430.

A first pinion gear 431 to transmit driving force to the slide member440 and a first drive motor 432 driving the first pinion gear 431 may beprovided on the first arm member 430.

A second rack gear 441, engaged with the first pinion gear 431 so as toreceive driving force transmitted from the first pinion gear 431, and asecond pinion gear 442 to transmit driving force to the second armmember 450 may be provided on the slide member 440. The second piniongear 442 is engaged with a first rack gear 433 fixed to the first armmember 430 and is rotated, when the slide member 440 moves in thelengthwise direction.

A third rack gear 451, engaged with the second pinion gear 442 so as toreceive driving force transmitted from the second pinion gear 442, maybe provided on the second arm member 450. As described above, both thefirst rack gear 433 and the third rack gear 451 may be engaged with thesecond pinion gear 442.

Through the above-described configuration, the second arm member 450moves in the lengthwise direction with respect to the first arm member430, and thus, the telescopic arm 400 c may be extended or retracted inthe forward or backward direction.

FIGS. 8 to 12 are views illustrating a process of covering a productwith a shrink film through the packing unit of FIG. 1. Hereinafter, theprocess of covering the product with the shrink film through the packingunit in accordance with an example embodiment of the present disclosurewill be described with reference to FIGS. 8 to 12.

FIG. 8 illustrates a state in which the telescopic arms 400 a, 400 b,400 c and 400 d of the packing unit 100 are maximally extended forwardsbefore the product 10 is covered with the shrink film 60. As shown inFIG. 8, when the opening unit 40 spreads the shrink film 60, thetelescopic arms 400 a, 400 b, 400 c and 400 d are maximally extended soas to grip the shrink film 60.

In this state, when the clamping fingers of the telescopic arms 400 a,400 b, 400 c and 400 d grip the shrink film 60, the telescopic arms 400a, 400 b, 400 c and 400 d are slightly retracted in the backwarddirection from the maximal extension position, and may thus tightlyspread the shrink film 60, as shown in FIG. 9.

Thereafter, when the elevators 300 a and 300 b move downwards in thestate in which the clamping fingers of the telescopic arms 400 a, 400 b,400 c and 400 d grip the shrink film 60, as shown in FIG. 10, forexample, the product 10 may be covered with the shrink film 60.

When the product 10 has been covered with the shrink film 60, thetelescopic arms 400 a, 400 b, 400 c and 400 d are retracted in thebackward direction, as shown in FIG. 11. Therefore, as shown in FIG. 12,the elevators 300 a and 300 b move upwards in a state in which thetelescopic arms 400 a, 400 b, 400 c and 400 d are retracted, and, atthis time, the transfer conveyer 20 moves, and thus, the product 10covered with the shrink film 60 may be transferred to the shrinking unit50 (with reference to FIG. 1), and the next product 10 not covered withthe shrink film 60 may be transferred to a region under the packing unit100.

Therefore, while in a shrink packing system, a transfer conveyer movesto transfer a product after an elevator has completely moved upwards, inthe shrink packing system 1 in accordance with an example embodiment ofthe present disclosure, a product may be transferred simultaneously withthe upward movement of the elevators 300 a and 300 b, and thus, apacking cycle time may be shortened.

As is apparent from the above description, in a shrink packing system inaccordance with an example embodiment of the present disclosure, aproduct covered with a shrink film may be transferred to a hot airshrinking unit through a transfer conveyer while a packing unit movesupwards after the packing unit has moved downwards and covered theproduct with the shrink film, and thus, the time required for a productpacking process may be shortened.

Further, since the packing unit of the shrink packing system inaccordance with an example embodiment of the present disclosure mayinclude two elevators supported by four supporters and two telescopicarms, the length of which may be retracted, are combined with each ofthe two elevators, vibration of the two arms when the elevators moveupwards and downwards may be reduced.

Although a few embodiments of the present disclosure have been shown anddescribed, it would be appreciated by those skilled in the art thatchanges may be made in these embodiments without departing from theprinciples and spirit of the disclosure, the scope of which is definedin the claims and their equivalents.

What is claimed is:
 1. A shrink packing system, comprising: a transferconveyer to transfer a product; a feeding unit to continuously feed ashrink film; an opening unit to receive the shrink film fed from thefeeding unit and to spread the shrink film; a packing unit to cover theproduct with the shrink film by moving in a direction of the productwhile gripping the spread shrink film; and a shrinking unit to shrinkthe shrink film covering the product using hot air, wherein the packingunit includes: a plurality of supporters arranged at both sides of thetransfer conveyer; a plurality of elevators supported by the pluralitysupporters and provided so as to be upwardly and downwardly movable; aplurality of telescopic arms combined with the plurality elevators so asto be slidable in the leftward and rightward directions, and provided soas to be extensible and retractable in the forward and backwarddirections; and a plurality of clamping fingers provided at the frontends of the plurality of telescopic arms.
 2. The shrink packing systemaccording to claim 1, wherein the shrink film is in the shape of anenvelope wound on a roll.
 3. The shrink packing system according toclaim 1, the plurality of supporters includes four supporters, theplurality of elevators includes two elevators, the plurality oftelescopic arms includes four telescopic arms, and the plurality ofclamping fingers includes four clamping fingers.
 4. The shrink packingsystem according to claim 3, wherein the two elevators are providedalongside the transfer conveyer.
 5. The shrink packing system accordingto claim 3, wherein the two elevators move upwards or downwardstogether.
 6. The shrink packing system according to claim 3, wherein thefour telescopic arms are extended or retracted together.
 7. The shrinkpacking system according to claim 1, wherein, when the opening unitspreads the shrink film, the plurality of telescopic arms are extendedin the forward direction, such that the clamping fingers grip the shrinkfilm.
 8. The shrink packing system according to claim 7, wherein, afterthe plurality of elevators have moved downwards while the clampingfingers grip the shrink film and then cover the product with the shrinkfilm, the telescopic arms are retracted in the backward direction. 9.The shrink packing system according to claim 8, wherein, when theplurality of elevators move upwards while the telescopic arms areretracted in the backward direction, the transfer conveyer moves totransfer the product covered with the shrink film to the shrinking unitand to transfer a next product not covered with the shrink film to thepacking unit.
 10. The shrink packing system according to claim 1,wherein: each of the elevators includes sliding rails provided in thelengthwise direction; and each of the telescopic arms includes a slidingblock combined with the sliding rails so as to slide in the leftward andrightward directions.
 11. The shrink packing system according to claim10, wherein: each of the elevators further includes a pinion gear and adrive motor driving the pinion gear; and each of the telescopic armsfurther includes a rack gear engaged with the pinion gear so as toreceive driving force.
 12. The shrink packing system according to claim10, wherein each of the plurality of telescopic arms includes a firstarm member combined with the sliding block, a slide member combined withthe first arm member so as to be movable in the forward and backwarddirections with respect to the first arm member, and a second arm membercombined with the slide member so as to be movable in the forward andbackward directions with respect to the slide member.
 13. The shrinkpacking system according to claim 12, wherein the first arm memberincludes a first pinion gear and a drive motor driving the first piniongear, and the slide member includes a rack gear engaged with the firstpinion gear so as to receive driving force and a second pinion gearwhich can be driven by the movement of the slide member, and the secondarm member includes a rack gear engaged with the second pinion gear soas to receive driving force.
 14. The shrink packing system according toclaim 13, wherein each of the plurality of clamping fingers is combinedwith each of the second arm members of the telescopic arms.
 15. A shrinkpacking system comprising: a transfer conveyer to transfer a product; afeeding unit to continuously feed a shrink film; an opening unit toreceive the shrink film fed from the feeding unit and spreading theshrink film; a packing unit comprising two elevators provided so as tobe upwardly and downwardly movable, and four telescopic arms combinedwith the two elevators so as to be slidable in the leftward andrightward directions and provided so as to be extensible and retractablein the forward and backward directions; and a shrinking unit shrinkingthe shrink film covering the product using hot air.
 16. The shrinkpacking system of claim 15, wherein the shrink film is in the shape ofan envelope wound on a roll.
 17. The shrink packing system according toclaim 15, wherein, when the opening unit spreads the shrink film, thepacking unit moves downwards while gripping the shrink film under thecondition that the product is stationary, covering the product with theshrink film.
 18. The shrink packing system according to claim 17,wherein, when the product is covered with the shrink film, the packingunit moves upwards and simultaneously, the product covered with theshrink film is transferred to the shrinking unit and another product notcovered with the shrink film is transferred to the packing unit.
 19. Apacking unit, comprising: four supporters arranged at both sides of atransfer conveyer transferring products; two elevators supported by thefour supporters and provided so as to be upwardly and downwardlymovable; four telescopic arms combined with the two elevators so as tobe slidable in the leftward and rightward directions, and provided so asto be extensible and retractable in the forward and backward directions;and four clamping fingers provided at the front ends of the fourtelescopic arms.
 20. A shrink packing system to shorten a time of apacking process, comprising: a packing unit to cover a product withshrink film by moving in a direction of the product while gripping theshrink film; and a shrinking unit to shrink the shrink film covering theproduct using hot air, wherein when the product is covered with theshrink film, the packing unit moves upwards and simultaneously, theproduct covered with the shrink film is transferred to the shrinkingunit and another product not covered with the shrink film is transferredto the packing unit.
 21. The shrink packing system of claim 20, whereinwhen the packing unit moves upward, the four telescopic arms are fullyretracted.
 22. The shrink packing system of claim 20, wherein when thepacking unit moves in a downward direction to cover the product in theshrink film, then the four telescopic arms are partially extended.